Hi Everybody,

Would a 3lb difference per corner weight difference be felt in everyday street driving?

There was an old thread that beat this question to death! For street driving you will not notice any difference. If you are a "tracker", you will notice a difference. I recently upgraded wheels and tires. The better tires and rims made a big improvement and were actually heavier.

100lbs difference and you might notice a difference..

it's usually about 0.1sec difference per 100lbs reduced.

I assume he's talking about rotating weight. There probably isn't 100lbs of rotating weight to cut from the car!

I think that 3lbs is getting close to noticeable, but it depends on what you're doing with your car as to whether or not it'd be worth the money.

It really depends on the person.

I've done a fair amount of track driving... none of it in a Mini (yet).
dropping the all-season runflats (weight 30+ lbs) to a dedicated winter tire (Haka's in the 21+ range) is EXTREMELY noticible, even to my wife, who runs over curbs without really noticing.

I have become very sensitive to feeling what the car is doing wrt. slides/drift angels... you might be able to tell while cornering and hitting an imperfection.

BUT it really depends on you and how you drive your car.

HTH.

^ A change of tires is a lot different from a 3lb change in wheel weight...

To to OP - 3 lbs isn't very much. On the street, you won't feel much if any difference everything else being equal with regards to tire brand, tread and size.

I'd bet you wouldn't notice a big difference at an autox either unless you are already at the top of your game.

I just know that when I go from my summer tire setup, which are stock s-lites and stock dunlop runflats, weighing in at 48.6 lb to my winter tire setup weighing in at 42.4 lb. I can notice a big difference with normal street driving.

Basically the car pulls harder and faster in every gear and I find I can go to the next gear sooner because the car acts like it's not working as hard if that makes sense.

I hope he's talking rotating weight. 3lbs is still fairly small but will depend upon where it's at with regard to inertia.

Now if we're talking a four wheel scale of the car and 3lbs...you'd be luck to get that close repeatedly!

*note reference to heavier TIRE on same wheel. Inertia.

So how much wheel/tire weight reduction would make a street difference assuming the tread, width, and diameter being equal?

Hi everybody,

I am talking about a 3lb difference per wheel, everything else (including tire weight) being equal.

i think this is how you calculate (very generic) unsprung weight.
(correct me if im wrong. i won't bite)


3x4=12lbs

12x4 = 48lbs

you're not going to notice anything.

Hey Todd - Do you mean me or the original poster? I have different tires and wheels between summer and winter...

If only considering 3 lbs for each wheel in the same size diameter wheel then it's not much difference. For basic street driving- no difference.

If you look at the total weight of each wheel what looks like a little could be more.

Consider OEM MINI wheels 17" and look at 25 lbs S-lytes vs 22 lbs for another OEM wheel. Not much difference they are both heavy. An underpowered MINI would have to work a little harder to move these wheels.

Consider a very light 13 lb 17" aftermarket wheel vs another 16 lb wheel of the same basic dimensions. For any performance driving the 13 lb wheel is likely to be more responsive and for street driving more noticable since the total % of wheel weight loss is greater than with heavy wheels.

I always try to pick rims that are lighter when possible.

Tires will make a huge difference. I consider the overall merits of the tire more than just the weight. Tire size, fitment, tread pattern, wear and price are all factors. Some really good tires tend to weigh more while other tires tend to weight less.

Minihune, I trust your advise & wide experience on this matter. So what you are saying is at least -9 lbs difference from the heavy S-lites should make a difference (all other things equal/ the same). Anything less is insignificant for street driving?

100/4 = 25

25/4= 6.25lbs unsprung weight you'll notice a difference.
but you'll notice more in braking capacity than acceleration.

Thanks.

If you have heavy wheels say 23+ lbs each and loose about 5 or 6 lbs each that would be helpful and with any spirited driving and with good tires I think you would be happy. The more weight you reduce the better, the more sticky the tires the better.

You can increase speed faster and stop quicker if the wheels are lighter as mentioned above. For constant speed driving it doesn't make much difference.

Realize that light rims are also at risk for damage from hitting road hazzards or pot holes. Strong and lighter weight usually means higher prices. If you reduce weight without increasing strength then you need to be more careful.

Forged wheels tend to be strong and lighter than gravity cast alloy wheels.
A heavy OEM wheel can still be damaged by a pothole since you usually will use a lower sidewall tire that is stiff such as a runflat and stock 17" wheels.

Actually, lighter wheels make for a smoother ride, too.

Less unsprung weight = smoother ride, and suspension tracks the surface of the road better for more grip.

really? cause i found that my current 22lbs (?) wheels are smoother
than the 11.5lbs comps that i sold.

more to do with tires, the suspension makes is more complicated than just lighter is smoother.

Personally I can feel a the difference in the wheel weights. Braking is the biggest point where I can feel the difference. The negative power from the brakes is much higher than the engine so that is where you will feel the inertia difference the most.

I believe I would feel the difference in street driving. The actual times may not change much but the feel is different. I think my heaviest wheel/tires and lightest wheel/tires are about 8 lbs different. Night and day there. Of course, the light set is smaller and cornering at speed is day and night.

This is a comparison of stock MINI Cooper S tires/rims and stock Cooper tires/rims. It does not speak to stock v expensive, light aftermarket.

Ya, as ChiliXer said, tires obviously play a large part too - the sidewalls in particular.

But go pull do a search on "quarter car model", start solving equations, and you should see that less unsprung weight means less deflection to the car body, meaning more comfort.

We have mentioned rotating mass, and where the additional mass is located makes a huge difference. The closer the additional mass is to the center of the hub the less you will feel.

I went from stock 24lbs to SSR's 15 and non runflats and it made a huge difference. Surprisingly, it eliminated torque steer. The ride is rougher.

That's a good point that often gets neglected or forgotten:

A 2-3 pound lighter tire will have a larger effect than a 2-3 pound lighter wheel. It can be difficult to find the weights for tires, but TireRack typically has them listed under the Specs link.